Effect of Electron Beam Currents on Welding Quality of CLAM Steel for High Density Cooling Channels.

The blanket is the key component for fusion reactor. The China Low Activation Martensitic steel is being developed under wide collaboration in China, and chosen as the candidate structure material of dual functional lithium-lead (DFLL) blanket of fusion design study series reactor designs. The cooling plate (CP) is one of the key components of the DFLL blanket, and it is embedded with high density cooling channels (HDCCs). The CP can be fabricated with grooved base plate, thin strips and thin cover plate by electron beam welding (EBW) and hot isostatic pressing methods. The welding of thin strips with grooved base plate is one of the key issues of HDCCs manufacturing. In this work, the effect of electron beam currents (EBCs) on the EBW quality of HDCCs was studied. The microstructure and the microhardness of the optimized EBC joint were tested at as-weld and post weld heat treatment to check its quality. The results showed that no obvious defect was observed and the quality of the joint was sound. Preliminary testing verified the effectiveness of the EBW for the HDCCs fabrication. [ABSTRACT FROM AUTHOR]